Aston Villa have signed Scott Hogan from Championship rivals Brentford for a fee that could reach £12m.
Hogan, linked with a move to Premier League side West Ham, has scored 21 goals in 34 games for the Bees after joining from Rochdale in July 2014.
The League One side are due 30% of any fee received for the 24-year-old.
Aston Villa were beaten 3-0 by Brentford at Griffin Park on Tuesday, two hours before Hogan's move was confirmed.
"I'm delighted to be at a club like Aston Villa," Hogan told the club website. "With its history and tradition I can't wait to start working hard and helping the team.
"It all happened quite quickly. I'm looking forward to meeting my new team-mates and beginning a new chapter in my career."
|Villa's busy January|
|Transfers/loans in||Transfers/loans out|
|Sam Johnstone (Manchester United)||Pierluigi Gollini (Atalanta)|
|Henri Lansbury (Nottingham Forest)||Rudy Gestede (Middlesbrough)|
|James Bree (Barnsley)||Ashley Westwood (Burnley)|
|Birkir Bjarnason (Basel)||Jordan Ayew (Swansea)|
|Conor Hourihane (Barnsley)||Aaron Tshibola (Nottingham Forest)|
|Neil Taylor (Swansea)||Kevin Toner (Bradford)|
|Jacob Bedeau (Bury)||Aly Cissokho (Olympiakos)|
|Scott Hogan (Brentford)||Ross McCormack (Nottingham Forest)|
Villa have been busy during the transfer window, with Nottingham Forest captain Henri Lansbury, Barnsley skipper Conor Hourihane and Iceland international Birkir Bjarnason among their other January signings.
They have spent about £40m on strikers since being relegated from the Premier League last season, much of it by previous Villa boss Roberto di Matteo last summer.
Steve Bruce's side are 14th in the Championship table, 10 points below the play-off places.
BBC Sport reporter Ian Westbrook
Scott Hogan has made a remarkable recovery from two serious knee injuries to become one of the deadliest strikers in the Championship.
He joined Brentford in the summer of 2014 for £750,000 from Rochdale, but in his second appearance as a substitute suffered an anterior cruciate ligament injury in his left knee in a match at Rotherham.
He broke down again during his recovery period and, after 18 months out, was eased back into the side with two full and five substitute appearances at the end of last season, in which he scored seven goals.
Hogan continued his prolific form this season and, proving his fitness, played every minute of Brentford's first 25 Championship games of the season, barring injury time at Birmingham on 2 January, scoring 14 goals in the process and attracting growing attention from other clubs.
With reported bids from West Ham and minor injuries in January, his only other appearance this month was as a substitute at Chelsea in the FA Cup on Saturday.